I operate a small forum and somewhat solved the issue of being scanned by the bots by letting the users to decide whether their posts/threads are visible to una

I operate a small forum and somewhat solved the issue of being scanned by the bots by letting the users to decide whether their posts/threads are visible to unauthenticated users, or users with less karma than some threshold. They can either be completely hidden to them or hide their names and let just the post be visible.